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"Everyone needs to run their own campaign," Rubio told CNN's Jamie Gangel

Rubio has been attacked by his 2016 rivals over his voting record

Washington (CNN)Marco Rubio defended his heavily criticized absences from nearly one third of Senate votes this year, saying his presidential campaign requires him to be out on the trail, and dismissed suggestions that his call for delinquent federal workers to be fired was hypocritical.

"Everyone needs to run their own campaign," Rubio told CNN's Jamie Gangel in an interview that aired Sunday on "State of the Union." "I'm not missing votes because I'm on vacation."

Rubio, who has the worst voting attendance record in the Senate this year, has been attacked by his 2016 rivals over his voting record, especially front-runner Donald Trump, who called him a "lightweight senator" in a tweet last month. Scrutiny over Rubio's shoddy attendance record increased earlier this month when the Florida senator missed a key vote on defense spending to campaign in New Hampshire.

Rubio also explained remarks he made on the Senate floor this week when he said federal workers who don't do their jobs should be fired.